2023 AMSS Abstract Book

Gulf of Alaska | Fishes and Fish Habitats

Detection efficiency of an autonomous underwater glider-mounted acoustic receiver for acoustic tagged Pacific herring Presenter: Alysha Cypher , acypher@pwssc.org, Prince William Sound Science Center Hank Statscewich , hank.stats@alaska.edu, University of Alaska Fairbanks Rob Campbell , rcampbell@pwssc.org, Prince William Sound Science Center Seth Danielson , sldanielson@alaska.edu, University of Alaska Fairbanks, College of Fisheries and Ocean Sciences John Eiler , alaska.jeiler@gmail.com Mary Anne Bishop , mbishop@pwssc.org, Prince William Sound Science Center Autonomous underwater vehicles (AUVs) or gliders are increasingly being used with acoustic telemetry to evaluate fish movements while collecting simultaneous environmental data. We assessed the utility of an AUV equipped with an integrated acoustic receiver to detect Pacific herring ( Clupea pallasii ) within the inside waters of Prince William Sound, Alaska. A range test evaluated the effect of predictors, glider flight characteristics and environmental conditions, on detection efficiency of transmitters at varying depth. The AUV then performed repeated, adaptive transects within southeastern PWS to detect acoustic tagged Pacific herring. While distance from transmitters was the strongest predictor of glider detections, glider depth had a variable effect on detection efficiency which depended on transmitter depth and glider dive orientation. In comparison to stationary acoustic receivers, the detection efficiency of the glider- mounted receiver was less affected by environmental conditions and transmitter depth. Following a range test, the glider detected 30 Pacific herring transmitters without a priori knowledge of their location. Of these herring transmitters, 14 were presumed shed after repeated detections within the same area and two were detected at multiple locations, demonstrating the capacity of the glider to detect movements of migratory forage fish over relatively large areas.

Alaska Marine Science Symposium 2023 186

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